"Finding out the role each gene plays helps us to piece together the evolutionary path from Neanderthal to modern humans," study co-author Kaustubh Adhikari, a cell and developmental biologist at University College London, said in a statement. "It brings us closer to understanding how genes influence the way we look, which is important for forensics applications." [Bio-Art: 3D Printed Faces Reconstructed from Stray DNA]

Although many people think of nose shape as a purely aesthetic feature, researchers suspect that different nose shapes evolved in different environments, for different reasons, the study authors said.

"For example, the comparatively narrower nose of Europeans has been proposed to represent an adaptation to a cold, dry climate," said study lead author Andrés Ruiz-Linares, a biologist at University College London. "Identifying genes affecting nose shape provides us with new tools to examine this question, as well as the evolution of the face in other species."

To figure out what makes a nose, the researchers studied nearly 6,000 people from Colombia, Peru, Brazil, Chile and Mexico who had participated in the CANDELA study, an ongoing study of the biological diversity of people living in Latin America. The people in the study have a mix of Caucasian, African and Native American ancestry, creating a wide range of facial features. Past research from this population has identified genes that make people go gray.

The team analyzed the participants' facial features, and also did 3D reconstructions for 3,000 of the participants, to get exact measurements of their facial features.

Then, the team looked at the genomes of these people, and identified three genes known to drive bone and cartilage growth that also seemed to predict nose shape. Two genes, called GLI3 and PAX1, seemed to have a large effect on nostril width, while another, called DCH2, controlled nose pointiness. A fourth gene, called RUNX2, was associated with the breadth of the nose at the bridge.

Interestingly, three of these genes - GLI3, RUNX2 and DCH2 - seemed to have changed during modern humans' recent past, compared with in earlier times, such as during the evolution of archaic humans, including the Neanderthals and the Denisovans. This finding suggests that these genes have been under strong pressure from natural selection in the more recent past, according to the researchers.

, a designer and artist, and design fellow on Synthetic Aesthetics project, questions whether humanity could tolerate using synthetic animals to help perpetuate natural species and also clean up the environment that threatens them.

, and invites people to consider the implication of synthetic life. Specifically, it focuses on the the relationship between conservation, biodiversity and synthetic biology, imagining what four bio-engineered creatures could do if released into the wild.

This self-replicating biofilm acts as a protective coating on leaf surfaces to prevent airborne pollutants as well as fungal spores from damaging the plant. The biofilm traps the particles, but doesn't interfere with the leaf's ability to function. When the leaf falls at the end of the season, the trapped matter goes with it. The bio-waste is collected and processed by another synthetic creature, the Mobile Bioremediation Unit.

Reminiscent of a leaf or a slug, this critter is designed for bioremediation. It moves through a forest floor, disturbing the topsoil as it goes along, in search of soil with high acid levels caused by pollution. When it finds such dirt, it disperses an alkali hygroscopic fluid to neutralize the acid. The unit has two extra bases in its DNA, making it inedible to other animals. A genetic kill-switch limits the device to a 28-day lifespan.

This synthetic animal looks like a hedgehog at first glance, but its job is to rove the earth and collect and disperse seeds. It moves by flexing and contracting its chassis. Coarse hairs and rubbery spines on top are designed to collect and distribute seeds. The creature gets power from waste collected by the Mobile Bioremediation Unit and has a lifespan of 600 days.

This single-use device treats the infection that causes Sudden Oak Death. It begins as a tiny spore that establishes itself in oak trees. When a biochemical sensor inside detects the presence of infection in the tree, the synthetic organism begins to grow into a double-chamber bubble. The inner chamber produces an antipathogenic serum; the outer chamber serves as a pump to push the serum into the infection site. After it has injected the medicine, the pump deflates, decouples and falls to the forest floor, where it's picked up by a bioremediation unit.